Introduce HostID and de-couple Extensions from "script injection System" [browser side]

extensions/browser/api/declarative_webrequest/webrequest_rules_registry.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "extensions/browser/api/declarative_webrequest/webrequest_rules_registry.h"
 
 #include <algorithm>
 #include <limits>
 #include <utility>
 
@@ skipping 162 matching lines @@
   const Extension* extension =
       extension_info_map_->extensions().GetByID(extension_id);
   RulesMap& registered_rules = webrequest_rules_[extension_id];
 
   for (std::vector<linked_ptr<RulesRegistry::Rule> >::const_iterator rule =
        rules.begin(); rule != rules.end(); ++rule) {
     const WebRequestRule::RuleId& rule_id(*(*rule)->id);
     DCHECK(registered_rules.find(rule_id) == registered_rules.end());
 
     scoped_ptr<WebRequestRule> webrequest_rule(WebRequestRule::Create(
-        url_matcher_.condition_factory(), browser_context(), extension,
+        url_matcher_.condition_factory(), browser_context(),
+        HostID(HostID::EXTENSIONS, extension->id()), extension,
         extension_installation_time, *rule,
         base::Bind(&Checker, base::Unretained(extension)), &error));
     if (!error.empty()) {
       // We don't return here, because we want to clear temporary
       // condition sets in the url_matcher_.
       break;
     }
 
     new_webrequest_rules.push_back(
         IdRulePair(rule_id, make_linked_ptr(webrequest_rule.release())));
@@ skipping 208 matching lines @@
     RuleTriggers::const_iterator rule_trigger = rule_triggers_.find(*url_match);
     CHECK(rule_trigger != rule_triggers_.end());
     if (!ContainsKey(*result, rule_trigger->second) &&
         rule_trigger->second->conditions().IsFulfilled(*url_match,
                                                        request_data))
       result->insert(rule_trigger->second);
   }
 }
 
 }  // namespace extensions